Repeated-stress-testing machine.



J. B. KOMMEHS.

REPEAIED STRESS TESTlNG MACHINE.

APPLICATION men was. 1914 1,163,830. Patented Dec. 14, 1915.

3 SHEETS-SHEET 7.

Hi/masses: 1 I [raven/tor W4 7/ 51 1 Jesse B- KOITbfllfS WMW. W

jltowwys J. B KOMMERS.

REPEATED STRESS TESTING MACHINE.

APPLICATION FILED AUG S 1914.

1,163,830. Patented Dec. 14, 1915.

3 SHEETSSHEET 3.

, 7 [ill/676507 JsSG B. Komrnc-rs wiffi WW Wi/b 2165565 Affornaw JESSEIB. KO'MMEBS, OF MADISON, WISCQNSIN.

REPEATED-STBESS-TESTING MACHINE.

Specification of Letters latent.

Patented Dec. 14, 1915.

Application filed August 5, 1914. Serial No. 855,0.

To all whom it may concern:

Be it known that I, Jesse B. KOMMERS, a citizen of the United- States,residing at Madison, in the county of Dane and State of Wisconsin, haveinvented certain new and useful Improvements in Repeated-Stress- TestingMachines, of which the following is a full, clear, concise, and exactdescription, reference being had to the accompanying drawings, forming apart of this specification.

The subject-matter of the present inventicn is a repeated stress testingmachine. In testing specimens of steel and the like, it is customary tosubject the specimen to repeated stresses of a definite character and tocompare the qualities of variousspecimens by the ratio of the number ofthe stresses which the specimens can withstand before failure. It isalso customary to compare the efiicacy of the various heat treatmentsupon a given material by the ability of specimens to withstand repeatedstresses. In the machine which is thesubject-matter of the presentinvention, the specimen may be bent only in one direction or alternatelyin opposite directions until failure occurs.

In certain classes of tests, it is desirable to deliver a hammer blow tothe specimen in bending the same. A machine built in accordance with theteachings of my invention is capable of delivering such a blow whentesting a specimen. Means is also. provided for recording automaticallythe number of stresses to which the specimen is subjected before failurethereof occurs.

The object of the present invention is to provide an improved testingmachine for subjecting a specimen to repeated stresses.

A further object is to provide automatic means for registering thenumber of stresses to which the specimen is subjected before failure ofthe specimen occurs.

A still further object is to provide means for accurately determiningthe amount of flexure to which the specimen is subjected and todetermine the load corresponding to any such deflection, and a furtherobject is to improve and simplify the construction of testing machines.

In the drawings accompanying and forming a part of this specification,Figure 1 is a general plan view of the main operating parts of themachine when in position to test a specimen by repeated alternatestresses; Fig. 2 is an elevation of the machine when arranged todetermine the load corresponding to a given deflection of the specimen;Fig. 3 is a plan view, with parts broken away, of the slider mechanism;Fig. 4 is an elevation of the same; Fig. 5 is a view of a cross-sectionon the line 5-5 of Fig. 3; Fig. 6 is a fragmentary detail view, showingthe gripping mechanism and the impact jaws; Fig. 7 is an elevation ofthe jack shaft and crank disk; Fig. 8 is a front view of the crank disk,showing the mechanism for adjusting the throw of the crank; and Fig. 9is a cross-section of the crank disk on the line 99 of Fig. 8.

In Fig. 1, I have shown a cross-head or slider 10, mounted in the ways,11, upon the base 13. This slider is operated by means of a wrist pin14, through a connectin rod 15 and a disk crank 16. having a cran t pin17 of variable throw. The crank disk 16 is mounted on a shaft 18 havinghearings in the pedestal 19. The shaft 18 is driven by an electric orother motor 20, as by means of the belt 21 and driving pulley 22, whichmay be connected to the shaft 18 by means of the clutch mechanism 23.Upon the slider 10, adjustable blocks24 and 25 are mounted. Impact jaws26 and 27 are mounted on the blocks 24 and 25 and serve to flex thespecimen 30, which extends between them, when the slider 10 is moved byrotation of the crank disk 16.

In Fig. 2, I have illustrated the slider 10 as connected to thestationary deflection mechanism for determining the load necessary toproduce a given deflection of the specimen. This mechanism consists of abell crank lever 31, having its shorter arm 32 connected, bv means of aknife-edge 33 and yoke 34, to the slider 10. Adjusting means, such asthe turn buckle 35, may be provided for insuring the proper relation ofthe bell crank lever and the slider. The flexible coupling 36 may alsobe introduced into the connection to prevent flexing of the same. Thelong arm 37 of the bell crank lever is provided with a knife-edge 38 andyoke 39, to which a platform 40 may be attached for the suspension ofsuitable weights to produce the proper deflection of the specimen 30. Inorder to obviate the necessity for computing the weight of the leverarm, I emDlov a counterbalance for maintaining a. balance of the parts.By this means, I am able to read directly the'load required to produce agiven deflection.

The slider mechanism and associated parts is shown in detail in Figs. 3to 6 inelusive. The slider 10 consists of bearing members 42 (see Fig.5) to which is connected the crank pin 14 for imparting motion thereto.The slides 42 fit accurately into grooves 43 formed in the ways 11, theslides 42 being secured in said grooves by means of the guide plates 44,which are clamped to the ways 11 by means of the bolts 45. The ways 11are formed separately from the base 13. but are clamped to said base bmeans of bolts 46 extending through ears 47 formed upon the ways 11 andbase 13. A rectangular frame member 48 is clamped bv means of bolts 49to the slides 42. This frame bears rectangular kevs 50 let into a groovein the sides of said frame and secured the ein b means of the screws 51,shown in Figs. 3 and 5. The blocks 24 and 25 have rectangular grooves inthe edges thereof. fitting over the proiecting portion of the guide kevs50. The blocks 24 and 25 are slit, as indicated in Fig. 5. and areprovided with clamping bolts 52 for drawing the edges of the blockstogether, to grip the guiding kevs 50 in order to maintain the blocks 24and 25 in a predetermined position during the adjustment. The blocks areheld against outward movement by means of the bolts 52, which bolts maybe locked by suitable iam nuts. Micrometers 54and 55 are provided forobtaining an accurate adiustment of the blocks 24 and 25. These blockshave secured on their inner faces. bv means of the bolts 56 and 57. thehardened steel blocks 26 and 27 which form impact or hammer iaws forengaging the specimen 30 to be tested.

Figs. 4 and 6 illustrate the clamping means for gripping the specimenrigidly in the machine. A pair of clamping blocks 59 and 60 is clampedto the base 13 by means of bolts 61 and 62 passingthrou h the base andthrough the blocks. provided with hardened steel clamping jaws 63. whichare fastened to the blocks by means of the screws 64. These iaws arerecessed at 65 for a purpose to be explained later. A pair of bolts 66is threaded throu h the boss 67 to force the iaws together to grip the secimen 30. An abutment 68 is provided for the block 59 in order to allowsecure clam ing of the blocks 59, 60 by means of bolts 66.

In Fi s. 7. 8 and 9. I have illustrated the crank shaft and anadiustable crank disk for secur n a variable throw of the crosshead orslider 10. The crank disk 16 is slotted diametricall b an undercutgroove 70 inthe shape of a T-slot (see Fig. 9). A

slide 71. hearing the crank pin 17. is fitted closely in said groove.The slide 71 and pin These blocks are i 17 are moved in the guide bymeans of the bolt 72 which passes through the stationary lug 73 andthreads into :1 lug 74 on the slide 71. pointer 75 is attached to theslide and indicates on the .scale 76 the distance from the center of thedisk 16 to the center of the pin 17. In other words, it indicatesone-half the throw of the crank. A lock nut 77 clamps the bolt 72, bymeans of the collar 78, firmly against the lug 73, and a lock nut 79 maybe emploved for locking the bolt 72 in the lug 74. The pin 17 isthreaded axwhy for the reception of a set screw 80 bearing against thebottom of the slot 70.

The meansfor countin the number of strokes made by the slider 1s shownin Figs. 3, 4 and 7. A. Veeder counter 81 has a crank 82 provided with apin 83. A spring normally holds the pin 83 in engagement with the innersurface of the eccentric 84. Upon failure of the specimen, the tensionof the spring 85 is automatically released and the operation of thecounter is halted. T secure this cited; by means of the followmgapparatus: The spring 85 is normally held under tension by means of alever 86, pivoted at 87 on a standard 88 mounted ona guide-plate 44. Theopposite end of the lever 86 is attached, by means of the spring 89, tothe clamp 90, which clamp is fastened to the specimen 30. A spring 91attached to the lever 86 and to the post 88, tends to push the lever 86in such a manner as to throw the counter mechanism out of action. Thespring 89 normally holds the lever 86 against the abutment 92 on thepost 88, so as to hold the lever in a. definite position so long as thespecimen is intact. Upon failure of the specimen, the broken end thereofrises and, under the influence ,of the spring 91, the lever 86 is tiltedin a clockwise direction and the pin 83 drops down out of the influenceof the eccentric.

The adjustment and operation of themechine are as follows: Assume thatit is de sired to test a specimen by alternate flexures. The specimen isfirst clamped in the jaws 63 by means. of the bolts 66. The bolts 61, 62are tightened to hold the parts in position and the slide 71, hearingthe crank pin 1 is adjusted in the crank disk 16 to obtain a definitethrow of the slider .10. The amount of eccentricity of the pin 17 on thecrank disk 16 is half of the throw of the slider. This adjustment issecured by turning the bolt 72 until the proper eccentricity has beenobtained. The bolt 80 is then tightened to'hold the slide 71 in the slot70 and, thereafter, the lock nuts 77 and 79 are tightened. If it isdesired to deliver a blow to the specimen before the same is to bedeflected, the blocks 24 and 25 are separated the proper distance tosecure such a result.

As previously indicated, it is possible to secure by this machine adeflection without crank and slider.

1,1ea,sao

a blow, either repeatedly in the same direction or alternately inopposite directions, or to deliver a blow before each of saidoperations, the desired result being secured by a proper-adjustment ofthe blocks 24 and 25 so as to give greater or less loss of motion whenthe slider 10 is thrown to and fro. When the impact jaws 26 and 27engage the specimen 30, no blow is delivered, as the lost-motion iszero. In this case, the deflection will be equal to half the throw ofthe By allowing lost motion a greater blow will be struck with suchdefiection, but the same deflection can be secured by increasing thethrow of the crank by the adjusting means shown in Figs. 7, 8 and 9.

Suppose a specimen is to be tested by a three-quarter inch impact and adeflection of one-quarter inch, the specimen being three-eighths inchround material. To obtain this eifect, the slider 10 must have ahalf-stroke of three-eighths inch, plus onequarter inch or crank pin 17is first set for this half-stroke and then the full stroke is accuratelymeasured by means of the scale 93 and the vernier 94, shown in Fig. 3,upon theside of the plate 44 and the frame 48, respectively. When theexact stroke has been'obtained, the slider 10 is set at the middle ofits stroke by means of the scaleand vernier. erfectly straight standardthree-eighths inch specimen is. then fastened in the gripping blocks 63and the blocks 24 and 25 are loosened upon their slides, so as to befreely adjustable by means of the screws 52 and 53. The block 24 or 25is then moved until its impact jaw is brought into contact with thespecimen. The contact of the block may be determined by means of thequick adjusting micrometer 54, which is preferably provided with ayielding or ratchet pressure mechanism, as is well-known in the art.-Assume that the micrometer reads 0.125 inch. The micrometer is thenmoved backward three-eighths ofan inch, making a total reading thereuponof 0.50 inch. The screws 53 are turned back until the block is just incontact with the micrometer. At this point, the block is clamped inplace by means of the screws 52. This clamps the block against the guideand, thereafter, the screws 53 are brought against the block and set bvmeans of the lock nuts. The same operation is performed for both blocks24 and 25, so that the setting shall be accurate. The standard bar isremoved and the de- 6 sired specimen inserted in place thereof.

The clamp 90 for governing the counting mechanism is secured to thespecimen and the motor 20 is started. As soon as full speed is attained,the clutch mechanism 23 is operated and the machine operates to test thespecimen 30. Upon failure of the specifive-eighths inch. The

.men, the counting mechanism is automatically rendered inactive and thetesting machine may be stop ed by throwing out the clutch. mechanism 23.

It is noted that the frame of the machine is split, as shown in Figs. 4and 5-, and secured by means of the bolts and lugs 46, 47, and endwisemotion is prevented by means of the key 58. By this construction, it ispossible to inter ose a block of definite strength between t e base 13and the ways 11, so as to test a greater free length of specimen. It isnoted that the gripping jaws 63 are raised, as shown more particularlyin Figs. 4 and 5. This is to serve as a marking means for the specimento indicate that the same has been gripped in the jaws for testingpurposes. It is also possible to tell by the mark of the jaws upon thespecimen whether any slipping of the specimen has occurred during thetest. This is a valuable aid in determining the sufficiency of the test.

If it is desired to determine the amount of load required to produce agiven deflection, the connecting rod 15 is disconnected from the crankpin 17. This may be effected by withdrawing the key 95, shown in Fig. l.The bell crank lever 31 is attached to the slider 10 and, by properadjustment of the turn-buckle 35 and by placing suitable weights uponthe platform 40, the specimen is deflected by the amount which it isdesired to produce. This deflection may be read by means of the scaleand vernier 93, 94, shown in Fig. 3. The load maybe readily determinedinasmuch as the relation of the lever arms 32 and 37 is fixed.

From the above description, it can be seen that I have provided atesting machine embodying a number of important and useful features,suitable for obtaining comparisons between various specimens. Anydesired form of specimen may be tested by changing the gripping jaws 63.Among other advantages of the machine the following may be pointed out:The parts are adjustable, so that the stroke may be quickly changed and,by means of the scale and vernier, accurate measurements may be made;the adjustment for setting the hammer or impact dies is very accurateand readily manipulated; the machine may be set to test specimens ofvarious lengths, as well as various shapes; the amountof hammer blow orimpact may be varied for a given deflection and, reversely, thedeflection may be varied for a given impact; the load corresponding toany deflection may be accurately determined and, from this, the bendingmoment to which the specimen has been subjected may readily becalculated; the counting mechanism automatically records the number ofworking strokes or fiexures, and the counter ceases to record when thespecimen is ruptured; the dies in Vihile I have described the saidmachine with considerable particularity, I do not intend thereby tolimit my invention by such description, but intend that the same beconstrued only as a full disclosure of an operative embodiment for thepurpose of complying with the statutes.

\Vhat I claim as new and desire to secure by Letters .Patent of theUnited States is the following:

1. In a testing machine, means to grip a specimen, means to flex saidspecimen alternately in opposite directions, means for measuring theamount of flexure produced and means for determining the force-requiredto produce said amount of flexure, said flexing means having adjustingmeans to cause said flexing means to strike a blow upon said specimenbefore flexing the same.

2. In a testing machine, means to grip a specimen, means to bend saidspecimen repeatedly, said bending means including a. pair of impactjaws, means to cause said impact jaws to strike a. blow upon saidspecimen, upon bending the same, said bending means being provided withmeans for measuring the amount of bending produced.

3. In a testing machine, means to grip a specimen, means to flex saidspecimen alternately in opposite directions, said flexing means havingmeans for measuring the amount of flexure produced and having impactjaws separated forstriking a blow upon said specimen before flexing thesame.

4. In a testing machine, stationary means to grip one end of a specimen,means engaging the other end of the specimen to bend said specimenrepeatedly to a predetermined deflection, and means to determine theforce necessary to produce said deflection.

5. In a testing machine, stationary means to grip one end of a specimen,means engaging the other end of the specimen to bend said specimenrepeatedly to a predetermined deflection, means for measuring the amountof deflection and means to determine the force necessary to produce saiddeflection.

6. In a test machine, means for holding a test specimen, a base, an openframe mounted on said base, said specimen projecting through said frame,means to impart a reciprocating rectilinear motion to said frame tocause the same to bend said specimen repeatedly, means to measure thestroke of the frame and means to set said frame at the middle of itsstroke.

7. In a testing machine, a base, jaws mounted on said base for grippingone end of the test specimen, ways mounted on said base, a slidermovable in said ways, impact jaws mounted on said slider, said jawsadapted to engage the free end of said specimen to bend the same, meansto impart a reciprocating motion to said slider in said ways andmeasuring means attached to said slider for determining accurately thestroke of said slider.

8. In combination, a base, a pair of clamping blocks, hardened steeljaws removably' secured to said clamping blocks, means to preventrelative movement between said jaws and said clamping block, and meanscooperating with said blocks for causing said jaws to engage a testspecimen.

9. In combination, a base, a pair of clamping blocks, hardened steeljaws removably secured to said clamping blocks, means secured to saidblocks for causing said jaws to engage one end of a test specimen, asliding frame mounted for rectilinear movement on said base, impact jawson said frame for engaging the specimen to bend the same and means fordetermining accurately the stroke of said sliding frame.

10. In combination, a base, gripping means mounted on said base forholding one end of a test specimen, ways mounted on said base, a slidermounted on' said ways, said slider comprising a rectangular frameinclosing the free end of said test specimen, a crank, a connecting roduniting said crank and said slider, means to rotate said crank, means toadjust the throw of said crank to vary the throw of said slider andmeans engaging the free end of the specimen to bend the same, said meansbeing mounted on said frame.

11. In combination, a base, means mounted on said base for holding atest specimen, a slider mounted on said base, means on said slider forengaging said test specimen, a lever connected to said slider, a weightconnected to said lever to move said slider against said test specimen,a rotatable crank, and a connecting rod mounted on said crank andconnected to said slider.

12. In combination, a base, means mounted on said base for holding atest specimen, a slider mounted in ways on said base to engage said testspecimen, a lever connected to said slider, weighing means connected tosaid lever to cause said slider to deflect said specimen, a scalemounted on said base, a vernier mounted on said slider adjacent to saidscale to measure the deflection of said specimen.

13. In combination, a base, means mounted on said base for holding atest specimen, ways mounted on said base, a slider mounted in said waysfor engaging said specimen, means to impart to said slider areciprocating motion and means independent of said latter means fordetermining the amount of alternate deflection of said s ecimen, a,

weighing lever connectable to sand slider to determine the amount offorce required to produce a given deflection of said specimen. 15. Incombination, a base, stationary means mounted on said base for holdingone endof a test specimen, ways mounted on said base, a slider mountedon said ways, said slider engaging the free end of said test specimen, alever connected to said slider, a weight connected to said lever tocause said slider to deflect said specimen, a scale mounted on said baseand a vernier mounted on said slideradjacent to said scale to determinethe amount of deflection of said specimen. a 16. In combination, a base,means for holding a test specimen mounted on said base, ways mounted onsaid base, a slider in said ways, said slider adapted to engage the testspecimen, a crank shaft, a connecting rod for imparting a reciprocatingmotion to said slider, a standard mounted on said ways, a clamp forengaging a specimen, a

lever mounted on said standard and connected to said clamp, a cam onsaid crank shaft, counting mechanism held in operative engagement'bysaid lever with said cam.

17. Incombination, a base, means for ripping a test specimen mounted onsaid ase, rectilinear ways mounted onsaid base,.

a slider in said wa s, a crank disk mounted for rotation, a cran pin ofadjustable throw mounted on said crank disk, a connecting rod betweensaid slider and said crank pin and a setscrew passing through said crankpin and enga ing said crank disk.

18. In mec anism of the class described, a

crank disk mounted for rotation, a slot cut.

diametrically across the face of said crank disk, a slide bearing acrank pin mounted in said slot, a slider connected to said crank pin andmeans to hold a test specimen for engagement with said sliderfmeans toad ust the eccentricity of said crank pin, a set screw passing throughsaid crank pin and engaging said crank disk.

19. In combination, a crank shaft, a crank disk mounted thereon, aT-slot in the surface of said disk, a slide mounted in said slot, acrank pin mounted on said slide, means to adjust the eccentricity ofsaid crank pin, a clamping bolt passing through said crank pin to engagesaid crank disk and a slider connected to said crank pin for variablethrow thereby.

20. In a machine of the class described, a crank shaft bearing a crankdisk and having a dove-tailed slot in the sudface of said disk, a slidemounted in said slot, a crank pin mounted on said slide, means to adjustsaid slide, a scale mounted on said disk, a pointer mounted on saidslide, a clamping bolt passing through said crank pin and engaging saiddisk and a slide connected to said crank pin for variable throw thereby.

21. In a machine of the class described, gripping jaws comprising a pairof hardened steel blocks, one of said blocks having a depressed portionwith a sharp shoulder to make a definite mark upon the test specimenwhen the same is ripped.

22. In a machine of the class described, a base, means for grippin atest specimen mounted on said base, a pair of ways, a scale mounted onone of said ways, a sliding member mounted in said ways, a verniermounted on said sliding member adjacent said scale, a crank shaftbearing a crank, a connecting rod connecting said crank and said slidingmember to impart a reciprocating motion to said sliding member, andmeans to adjust the throw of said crank.

23.. In combination, a base, jaws mounted on said base for gripping atest specimen, waysmounted on said base, a slider mounted in said ways,a frame mounted on said slider, adjustable blocks mounted in said frame,impact ja ws for engaging said specimen mounted on said blocks, andmeans for imparting a reciprocating motion to said slider.

24. In combination, a base, jaws mounted on said base for gripping atest specimen, ways mounted on said base, a slider mounted in said ways,a frame member mounted on said slider, said frame member bearing guides,adjustable blocks mounted in said guides, and means to cause said blocksto grip said guides.

25. In combination, a base, jaws mounted on said base for gripping atest specimen, ways mounted on said base, a slider mounted in said ways,a frame member mounted on said slider, said frame member bearing guides,adjustable blocks mounted in said guides, means to cause said blocks togrip said guides, andadjusting screws for moving said hlocks dh saidguides.

26. In dombination, a base, jaws for ripping a test specimen mounted onsaid ase, a frame mounted on said slider, adjustable blocks mounted insaid frame, micrometer means for determining the position of saidblocks, and clam ing means for holding said blocks in pre eterminedposition in said frame.

27. In a slider for a test machine, a frame having guides, a pair ofblocks mounted on said guides, means to cause said blocks to grip saidguides, micrometer means mounted on said frame to adjust the position ofsaid blocks, and hammer jawsmounted on said blocks.

28. In a testing machine, a base, means mounted on said base to grip oneend of a test specimen, ways mounted on said base, a slider on said waysfor engaging and flexing said specimen, a crank shaft for operating saidslider, a cam mounted on said crank shaft, a counter having an operatingarm for engaging with said cam and means connected to the test specimenfor removing said arm fro engagement with said cam upon rupture o thespecimen.

29. In a testing machine, a base, a pair of clamping blocks mounted onsaid base, jaws mounted in saidblocks, said jaws having longitudinalgrooves therein for holding a test specimen, said jaws having recessesacross said grooves, said recesses having shar edges for makingmarksupon said specimen, and means for causing said jaws to grip a testspecimen.

In witness whereof, I hereunto subscribe my name this 28th day of July,A. D. 1914. 25

JESSE B. KOMMERS.

Witnesses:

WILLIAM T. KELsEr, EMIL CADY.

It is hereby certified that in Letters Patent No. 1,163,830, grantedDecember 14,

1915, upon the application of Jesse B. Kommers, of Madison, Wisconsin,for an improvement in Repeated-Stress-Testing Machines, an error appearsin the printed speeificationrequiring correction as follows: Page 5,line 74, claim 20, for

the word slide read slider,- and that the said Letters Patent should beread with i this eorrection therein that the same may conform to therecord of the case in the Patent Ofiice.

Signed and sealed this 25th day of January, A. 1)., 1916.

R; F. WHITEHAED,

Acting Commissioner of Patents.

[BELL-1

